Chandra X-ray Image of NGC 4555
NGC 4555 is unusual because it is a large elliptical galaxy that is not
part of a larger group or cluster. This allowed researchers to use
Chandra data to show that the galaxy is embedded in a cloud of
10-million-degree-Celsius gas. These X-ray observations of NGC 4555 confirm that an isolated, elliptical galaxy can possess a dark matter halo of its own.Scale: Image is 8 x 6.5 arcmin per side.(Credit: NASA/CXC/E.O'Sullivan et al.)

DSS Optical Image of NGC 4555
This image from the Digitized Sky Survey (DSS) shows the elliptical galaxy NGC 4555 in visible light. The field of view (left) is the same as the Chandra image. The wide-field DSS optical image (right) of the region surrounding NGC 4555 includes the large spiral galaxy NGC 4565, also known as the "Needle Galaxy," in the bottom left.Scale: Close-up image is 8 x 6.5 arcmin; Full-field image is 88 arcmin per side.(Credit: X-ray: NASA/CXC/E.O'Sullivan et al; Optical: Palomar DSS)

2MASS Infrared Image of NGC 4555
This image shows the elliptical galaxy NGC 4555 in infrared light as observed by the 2 Micron All-Sky Survey (2MASS). The field of view is the same as the Chandra image.Scale: Image is 8 x 6.5 arcmin per side.(Credit: 2MASS/UMass/IPAC-Caltech/NASA/NSF)